Grinding device



F. G. L. BOYER' GRINDING DEVICE Filed Jan. 8, 1946 Patented Aug. 16, 1949 2,479,095 I ;GRQIND I "I Ehe ,pnesent winv en tiqn yelates 110' grinding xg et'hoc le .and..deviees,.a1r 1d 'has for its. primaljy qhgieetLthe provision of an accurate method and appa t'atus for .removing protubel anees such as Welds, speeifiea uy electrolytic welds, in extensive, fihe wfie pl n su a e art ul ly of 1 1 1. 9 sheet -metal, which surfaces should not he cut qlgwggi r otherwise disturbed by the grinding o filjaition. Another v.(ijbject .of the invention is f the igeyi sipg; .p'f a eceurate method andapparetus 59, in i n ex en mela su i e o ue im e ni t at t e ent e de m (b on Lo aid 99 h Su i-ac f s adv t e us y-t ayereed wa the n ece w i e in c ra ly ma'jnteiped in .a .true ,plene. ,Qther',obje cts fanffl advantegesbf theI.invehtienwillgbeeome apperjen't mm-theiolls ie 'e .grintion- Th nvent n b wh t these b qt a e ed w l b id r d by eier nQ tohe a9; e eying grewlnei whic Fi u e .1 iepreie e iewfin i levatien an pa t sec f a v i zii ihe itiqn et' ptoiw In ime an electro ytic llle f and 3 m? wee -eve etens in the ripp e 9 i hi g both u ia l s 31 i e1 i et 'bbtki l y ded J'bin Etefe''rrihgto the drawing the :gjjpgiipg wheel U ispm ded with .s itahlemeens or 'driv n .1 1. ng spee s syit fi to he 'mete li fbein endthe -s zef nid t e o e u e It te wsl linb nie .dire l he s a flue m or 1 t p er ia pqmplete' ind g This umt is mounted i or e tica 'd l ne l j e "1 whi h impve ns fi b y meeeauelw w ded"with hw el v s; not sh0w r 1 ,"t0 insure the nefciessje ry tightness and freedpm from yihration -inthe slide. Vertical adjustment is provided b means Qfthe hand. heel l "i r 1the usual manner and s the nm n d ne p' r ewvs s gwing its amount may be ecgurgtglycphtrolledhy means qft he'miepqmeter dial 5 E.

Lateral 'movementqr 'cross'feeel of the grinding Lllfiijmgy he provided by mounting-the vertical Ways [4 one hbrizentallysli-qing carriage 2 l'which d eis fb ftp provide the traverse or Working ffihe gzim'iing device. "To "guide the entqftarriage 30,'g u.ides 34 are provided org "sliding iheafing :3 l "to cooperate with tradk 53. These gfifiies' "are made 'rif sufli'ien't length :flpn'giitra'k 3'3 *to providea gviide of ample strength "and accuracy, and-may "if eiesireii be prpvj aed with'atijustelhle gibs to prevent undue filayenfl' take =u-p -"for weer. *Thegu'iiiing surfaces ion tree are eidventageously sflbstantiiaiily 'horizenteilend-wither rvertical er undercut in-rthe we -knew'nenanner, to=prevent a,ny tendenjqy tsiweriis -lift1ng'-'df the carriage 30 upward from its proper ila-ne or motion ear-mg fits opera tiqn, since any slight or momentary' li fting rj'esult hg e*correspending'inaecuraeyof the g-reund sujfap'e.

"*Ihe tralversing mdtiendf' earri'age 30, carrying the grmflingvnit, may' beprodueed in any con.- veriiezgt-enenneras by apinion A l mountedren fihe earfiage enfl *m eshing with a stationar resek 42'. Phep'inion i-l -m ay be driven'fby bevel gear 43 meshes with :bevl pinion 44 which tam is Qlfiven b-y sfilined sl-mft 15 -in a usual manner. spl-ined sheftflimay in -tum be 'by aflmotorfl through the medium of a belt ="4q '{enii pulieys J8, 19. The -traverse "speed may be'waa ied by the use of cone 'ipu'lleys at 118, lfl 'end/er by the use fifewafljusteiblespee'd motor at 15. -fionvefltmnal adjustable mehanicel =01 letfleell stops andbr :reversing devices, mi!- showm may bepmvidediif desired.

The *upperp'anfi lower -surtaces :of i guide tracks 33 "are *weeuratly paraliel. flhaese tracks are fm ther firmlyqoined togetheraiateea'chend bye; l igiii eross mexrrberfifl whichmo'ss members unite the whale intoia :stnuctureewhich :hasiits upper mm! lower surfazces aeeurately *plane and pareiflel. F The lengthzof the*t1ac=ks :33 ahd. their lateral spaiein'gpend the :eorresponding length 15f ma e se be pm d with ad us a e e'noi 119M nd Slide on q izo' a t l w e erossieed may be "accomplished in, the known mann r y e s "of a crew 2.3 r v e w h hand Wheel F24 n la mic m teyd a 2 or acpurately measuring the7l novelr lje 1'11; Obvigusly,

autqmat feed, 'aq ustme t, and i de i s 0 types well known in the 'mechinetool ert can be o ided, in aip 'd t on to th handwh elizt for i Op at on,

The hor ontal ways. "22 are unted on, 0

formed integrally th, a carria e '9 WIl ChE p pviq g w th s idin b i g 1 and BZ'Whi imedditien to ithe' stmemres shown, *thene'zmay afivazitageous-lybespmvifleiifthe customary mieam forvcirefl lating eolemt'ito theapoint of contact between the eminding :wheel and athe work, ethe cenvmtienzl szifety iguarflsliamundithe grinding wheel, :geaa's, .Ibelts; eta, and :usual :means :fO

-' protecting isliding sand rotating bearings :from

sibrasi ve dust.

' Whempeeiflemmhofliment ot myinventionehewp in the drawing isxaimabchine particularly: adapted for removingfithezexeessrmetalzfmm anaelectrnlytieally *wiiied -11 oin't between the ends" of .-=a "metal belt fer use as acasting surfaeexinithe.manufae! tu; e6f='p1aetie=i1ms "(met surfaced coated paper, anfl the' i'ike. "iA' *be1t for sueh' use is required to & ad ted 9 Slime-9 'slzltable h rize ita treiclss he upi mityeftt e ess d aeco t ui y m d 3 I, smoothness of surface which are free from interruptions by any joint present therein;

Because of the .thinness and flexibility desirable in belts for these uses, it is necessary to provide supports which will hold the parts to be ground, with the necessary rigidity, in preparation for and during the grinding operation.

These supports must hold the parts of thesurface to which the finished ground, surface must conform, firmly and accurately in a plane parallel to the plane of the tracks 33, i. e. the plane of motion of the grinding device. For this purpose the parts of the belt surface adjacent the welded joint are smoothly, firmly, and accurately held in the same plane, as by being soldered or otherwise cemented or fastened to co-planar portions of the surface of a bar 66, on opposite sides of a depression in which the part of the joint protruding on that side of the belt is firmly soldered or otherwise fastened, as illustrated in Figure 2. This soldering, cementing, or other fastening operation may be carried out as a part of the preparation for the grinding operation. However, in some processes for the manufacture of endless metal belts of the type and for the purposes set forth, the accomplishment of the welding operation involves fastening the parts as described, and joints made according to that process are ready for insertion into the grinding device and alignment with the plane of the guides 33.

Such an arrangement is illustrated in the drawing. Sheet metal parts 6| are joined by weld metal 62 which protrudes above, and is to be ground down to,the level of the surface of the sheets 6|. smooth and accurately plane surface of a heavy and extremely rigid metal base or support 63 which may be additionally stifiened by a plurality of ribs 64 and rest on firm and rigid supports such as beams 65. The tracks 33 carrying the grinding mechanism rest and are advantageously clamped in place upon the surface of the sheets 6| where they are supported on the base 63. The tracks 33 thus guide the carriage with the grinding device in a plane path accurately parallel to the surfaces of base plate 63 and of the sheets 6| supported thereon. As above described, the weld and adjacent sheet metal are firmly fastened to the relatively rigid metal bar 66. The bar 66 rests in a recessed channel 61 formed in base plate 63. The channel 61 may convenientlybe somewhat wider and deeper than the width and thickness respectively of the bar 66. The surface of the sheets 6| adjacent to the weld 62, which sheets are there firmly and smoothly fastened to bar 66, may then be adjusted into a plane accurately parallel to the surface of support 63 and to the plane of motion of the grinding device, as determined by the guides 33, flexing the sheet metal 6| to the slight degree that may berequired, by means of a plurality of hollow jack screws 68 which are threaded through the base plate 63. The parallelism may be checked, be-

The sheet metal rests fiat upon the fore grinding is initiated, in the customary manner by the use of a test indicator which may be mounted on carriage 36 and ride on the surfaces of sheet 6| where it isfas'tened to bar 66. In order that the far 66 and thereby the upper surfaces of the sheets 6|, 6| may be firmly held rather than merely supported, a plurality of screws 69, threaded into bar 66, are provided, These screws are advantageously passed through the hollow jack screws 68 to prevent unwanted bending stresses in bar 66. The pairs of screws 68, 69 are advantageously spaced at intervals sufli- 4 cient to make possible the correction of any warpage of bar 66 or other lack of flatness in the surface of sheets 6| where they are fastened to the: bar.

, It may be noted that the adjustment of bar 66' may be such as to maintain the surface of sheets 6|, where they are attached to the bar 66, in, or parallel to and above, the plane of the surface of the sheets 6| where they are supported on base 63. They are advantageously never adjusted to a position below this plane because of the danger of bending the sheets and of cutting into their surface at the extremities of the cross feed of the grinder.

With the work thus set up, the grinding operation is carried out as follows: The motor I2 is set in motion, rotating the grinding wheel II at suitable cutting speed. The motor 46 is then set in motion, starting the traversing movement of the grinding mechanism. The automatic stops or reversing mechanisms, if provided, are set to give the required length of traverse. By means of hand wheel IS, the grinding wheel H is lowered until it just touches the high point of the work. The speeds and feeds are thereafter controlled, as is usualin grinding practice, and the operation is continued. until all of the weld metal protruding above the level of the adjacent surface of the sheets 6|, has been removed. The usual precautions are advantageously taken in the finishing cuts, to give the required surface finish.

The belt is then removed from the machine, unsoldered from bar 66, turned over and soldered, on its freshly ground surface, to a smooth surfaced bar 66, as shown in FigureB. It is then reinserted into the machine and the block 66 is fastened in recess 61 and leveled as was bar 66. The protruding weld metal is ground from this side in the manner described, so that the weld when unsoldered from bar 66' is of the same thickness as the adjacent parts of the belt, as indicated in Figure 4, and the joint is free from surface discontinuities.

In order to facilitate the use of the device described, means are advantageously provided for lifting tracks 33, together with the entire grinding mechanism, from the working surface 6|. For this purpose eye bolts H for attaching to an overhead crane or tackle block, may be provided on extensions of the cross members 53 which join the tracks 33, or at any other convenient location.

Obviously the grinding Wheel should traverse the entire width of the sheets 6|, i. e. the entire length of the weld, or other surface which must be ground, and therefore the tracks 33 should normally extend beyond this at each end. In order to maintain accurate parallelism of the plane of operation of the grinder with the plane surface to the level of which the grinding must be carried, it is usually desirable to clamp or otherwise secure the tracks 33 firmly in place. Clamping devices of known type may be used or, in case of the weld in the sheet metal 6|, the tracks may be screwed down to the base 63 beyond the edges of the sheets 6| by means of screws indicated at I6. To prevent bending stresses in tracks 33, a spacer of the exact thickness of metal 6| should be interposed between tracks 33 and base 63 at each of the clamps or screws 10. Furthermore, great care should be taken to exclude all dirt and foreign matter from between base 63 and sheets 6| and from between sheets SI and tracks 33.

The mechanism described, while primarily designed for removing protruding weld metal from Welded in 'mtdl mits; is iuscifi tor removing pmtubemmes sci fdim o'sttwny atype Efrem -sheet use'd'atozad vtmtage for removingtprotumances or srugo'sia ties from extensive rigid surfaces twill their su ''form without external support. Forthis purpose the tracks 33 carrying the griifding devices-"can ne set, and adwantage uslv clamped imposition, 1 su face from which the protuberames ,a'pesto round, without the use of bed ,plates 63 and its supporting struc'ture's.

If "is desired to operate on curved matirer thanm1ane siilcfaces, the devieetillustiated m he. provided with suitably curvedegu desahstead pf he str ight tracks andesides, so t at ":the s rindine wi eel will travel ip- 'ainsth con ung towthe urface to whichthe-metal is ts fished.

While not in general desirable, it is possible where narrow surfaces only, such as welded seams, are to be ground down by the device, to

omit the cross feed devices 22, 23, 24, 25, etc,

and use a grinding wheel having a width of face at least equal to the width of the metal to be ground, if the face of the wheel is kept accurately trued. However, I consider the form illustrated to be generally preferable even for grinding down narrow seams.

It will be obvious to those skilled in the machine tool art that many different known forms of guides, slides, feeding, traversing, stopping,'

and reversin mechanisms, driving means, etc., may be substituted for the particular forms shown, without departing from the present invention as defined in the appended claims.

I claim:

1. A device for removing protuberances from an extensive plane surface, which comprises a grinding device, a guide track for supporting and guiding said grinding device in a plane path, said track being adapted to rest upon said extensive surface, means for adjusting into accurate parallelism the plane path of said grinding device and the part of said extensive surface on which said grinding device is to operate, means for adjusting said grinding device towards and away from said surface, means for operating said grinding device, and means for moving said grinding device in said plane path.

2. A device for removing protuberances from an extensive surface of sheet metal, which comprises a grinding device, a rigid plane surface for supporting the sheet metal, a guide track for supportin and guiding said grinding device in a plane path, said guide track being adapted to rest on and be firmly clamped against the sheet metal lying on said rigid surface and thereby to serve to guide said grinding device in a plane substantially parallel to said surface, means for adjusting into accurate parallelism the plane path of said grinding device and the part of the sheet metal on which said grinding device is to operate, means for operating said grindin device, and means for moving said grinding device in said plane path.

3. A grinding device for dressing down the protruding parts of electrolytic welded joints in sheet metal, which joints, with the adjacent parts of the sheet metal, are firmly mounted on a relatively rigid metallic member, said device comprising: a support having a truly plane surface for supporting said sheet metal and a recess for receiving the metallic member on which the welded joint is mounted, said support havtion of' a isupportingibed plate, a cawity fn the bed plate, removable bars adapted to be attached to the surface of the sheet opposite the protrusion, positioning devices for supporting said bars in said cavity with their surfaces in a plane parallel to the surface of the bed plate, a grinder mounted above said bed plate, means for traversing said grinder, means for maintaining its grinding surface in a plane parallel with the bed plate during said traverse, and means for adjusting the grinder toward and from the bed plate.

5. The apparatus of claim 4 wherein the positioning devices comprise a plurality of hollow jack screws for locating said bars with reference to said bed plate and concentric screw means for maintaining contact between said bars and each of said jack screws.

6. A device for removing protuberances from an extensive surface of sheet metal, which comprises a grinding device, a rigid plane surface for supporting a sheet of metal, a guide track for supporting and guiding said grinding device in a plane path, said guide track being adapted to rest on and be firmly clamped against a sheet of metal supported on said rigid surface and thereby to serve to guide said grinding device in a plane substantially parallel to said surface, means for adjusting the part of the sheet metal on which the grinding device is to operate into accurate parallelism with the plane path of the grinding device and for firmly holding it in that position during the operation of the grinding device thereon, means for operating said grinding device, and means for moving said grinding device in said plane path.

7. Method of smoothing the surface of an extensive sheet of metal by removing protruding parts therefrom, which comprises: temporarily but firmly cementing a portion of the surface, directly opposite the area from which protruding parts are to be removed, to a more rigid body; supporting the sheet metal in the vicinity of said cemented portion on a rigid plane surface; then, by adjustment of said body, locally adjusting the cemented portion of the sheet metal to bring the portion of the surface from which the parts to be removed protrude, into substantial coincidence with a plane parallel to and at least as high as the surface of the supported portion; holdin said body, and the portion of the sheet metal cemented thereto, firmly in said adjusted position; movingan abrading device in a plane path parallel to said plane surface; and adjusting said plane path downward 7 as the protruding portions are cut down, until the desired removal has been accomplished.

8. The method of removing protruding metal down to the surface level of an extensive sheet of metal, which comprises: temporarily but firmly cementing a portion of the surface, directly opposite the area from which protruding metal is to be removed, to a more rigid body; holding the sheet metal near said cemented portion, on a rigid plane surface; then, adjusting said body and flexing adjacent portions of said sheetmetal as required to bring the portion of the surface from which the metal to be removed protrudes, into substantially accurate coincidence with a plane parallel to a predetermined 15 plane of motion of an abrading device, and at least as high as the adjacent portions of the surface of the sheet metal; holding said body, and. the portion of the sheet metal cemented thereto, firmly in said adjusted position; mov- 20 5 complished.

FREDERICK G. L. BOYER.

REFERENCES CITED The following references are of record in the 10 file of this patent:

UNITED STATES PATENTS Number Name Date 1,562,558 Hobson Nov. 24, 1925 1,716,279 Owen June 4, 1929 1,843,758 Bugbee Feb. 2, 1932 2,109,827 Mofiett W Mar. 1, 1938 2,282,145 Indge May 5, 1942 2,419,543 Ellis et a1 Apr. 29, 1947 

